June 5, 2011: Hot, Humid Conditions Return

With mostly cloudy skies over the area today along with a mostly south wind, today brought colder temperatures to the area, only reaching the upper 60s to lower 70s from NYC and further west and the mid to upper 60s in Long Island and southern Connecticut. A chilly air mass continued to stick over the region today, while heat started to build up in the southern United States. Today's chilly temperatures are the opposite of what we will be dealing with late this week, as heat from the central US spreads into the region, likely bringing temperatures well into the 90s in parts of the area on Thursday with the heat index potentially reaching the 100 degree mark.


Tomorrow's Outlook:

With the chilly air mass weakening, tomorrow will bring warmer temperatures to the area. With partly sunny skies and a north/NNW wind expected, high temperatures will reach the upper 70s to lower 80s from NYC and further west, with lower to upper 70s expected in Long Island and southern Connecticut. There is a low risk of an isolated shower or thunderstorm in the afternoon and evening hours, but the best risk of showers tomorrow will stay to the northeast of the area, in central New England.


Tuesday - Friday: Heat Wave Potential

Temperatures will continue to warm up on Tuesday, with more widespread lower to mid 80s from NYC and further west. There is the risk of scattered showers and thunderstorms on Tuesday, but any precipitation should be light and scattered.

By Wednesday, however, a very large area of heat will spread into the region, bringing the second potential for this year's first heat wave in the NYC area. Yesterday's NAM runs were outliers by keeping cold stuck over the Northeast, and today's NAM has backed away from this solution, supporting the GFS by spreading warmth into the Northeast. With mostly sunny skies expected along with a SW/WSW wind, temperatures will heat up into the upper 80s to lower 90s from NYC and further west, with mid to upper 80s expected in parts of Long Island and southern Connecticut as well, especially away from the coast.

Despite 90s returning into parts of the area on Wednesday, the hottest temperatures have yet to come. A large area of 850 mb temperatures above 20c will move towards the region, and will be over the area on Thursday. Unlike the May 30-June 1 warmth, when a strong storm very far to the northwest of the area pulled in the warmth, resulting in cooler temperatures in the NYC area and the Northeast, in this scenario we are seeing a relatively weak storm not too far to the north of the area, which will allow warmth to focus on the region.

With mostly to partly sunny skies expected along with a WSW wind, temperatures will surge into the lower to mid 90s from NYC and further west, and if we don't see any significant changes with the expected set up, even upper 90s are possible in parts of the immediate NYC area. Humid conditions are expected as well, which could push the heat index into the 100s for parts of the area.

The cold front's timing is uncertain, but it appears that it will move through sometime around Friday. Scattered showers and thunderstorms are possible with this cold front, and should the timing be slow enough as currently modeled, parts of the area may reach the lower 90s once again, making this an official heat wave. Temperatures will then cool down by next weekend into the lower 80s. Stay tuned for more information on the heat and potential storms late next week.